leds: leds-lp8860: Fix kernel-doc related formatting issues

Fixes the following W=1 kernel build warning(s):

 drivers/leds/leds-lp8860.c:105: warning: Function parameter or member 'lock' not described in 'lp8860_led'
 drivers/leds/leds-lp8860.c:105: warning: Function parameter or member 'client' not described in 'lp8860_led'
 drivers/leds/leds-lp8860.c:105: warning: Function parameter or member 'led_dev' not described in 'lp8860_led'
 drivers/leds/leds-lp8860.c:105: warning: Function parameter or member 'regmap' not described in 'lp8860_led'
 drivers/leds/leds-lp8860.c:105: warning: Function parameter or member 'eeprom_regmap' not described in 'lp8860_led'
 drivers/leds/leds-lp8860.c:105: warning: Function parameter or member 'enable_gpio' not described in 'lp8860_led'
 drivers/leds/leds-lp8860.c:105: warning: Function parameter or member 'regulator' not described in 'lp8860_led'

Cc: Pavel Machek <pavel@ucw.cz>
Cc: Dan Murphy <dmurphy@ti.com>
Cc: linux-leds@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>